Re: [2.6 patch] net/sctp/socket.c: add missingsctp_spin_unlock_irqrestore

From: Arjan van de Ven
Date: Sun Nov 26 2006 - 05:20:59 EST


On Sun, 2006-11-26 at 10:12 +0000, Al Viro wrote:
> On Sun, Nov 26, 2006 at 06:00:53PM +0800, Eugene Teo wrote:
> > This patch adds a missing sctp_spin_unlock_irqrestore when returning
> > from "if(space_left<addrlen)" condition.
> > if (copy_to_user(*to, &temp, addrlen)) {
> > - sctp_spin_unlock_irqrestore(&sctp_local_addr_lock,
> > - flags);
> > - return -EFAULT;
> > + err = -EFAULT;
> > + goto unlock;
>
> > + sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
> > + return err;
> > }
>
> You do realize that it's obviously still badly broken, don't you?
> copy_to_user() under a spinlock is a recipe for deadlock, especially
> if you've got interrupts disabled...
>
> I have a beginning of locking fixes in that shitpile, but it's incomplete
> and bloody painful ;-/
> -

do your patches also remove the empty abstraction of the sctp_ prefix
around the spinlock use in sctp ?


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